Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Estimated useful life [Abstract]
Amortization expense	$ 224	$ 339	$ 676	$ 1,025
Intangible assets, net [Abstract]
Gross Carrying Amount	8,839		8,839		8,852
Accumulated Amortization	(7,189)		(7,189)		(6,519)
Net Carrying Amount	1,650		1,650		2,333
Trademarks [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	1,278		1,278		1,278
Accumulated Amortization	(799)		(799)		(702)
Net Carrying Amount	479		479		576
Trademarks [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			1 year
Trademarks [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			10 years
Contracts - third party [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			7 years
Intangible assets, net [Abstract]
Gross Carrying Amount	3,650		3,650		3,650
Accumulated Amortization	(3,129)		(3,129)		(2,738)
Net Carrying Amount	521		521		912
Contracts - owned equipment [Member]
Intangible assets, net [Abstract]
Gross Carrying Amount	3,911		3,911		3,924
Accumulated Amortization	(3,261)		(3,261)		(3,079)
Net Carrying Amount	$ 650		$ 650		$ 845
Contracts - owned equipment [Member] | Minimum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			5 years
Contracts - owned equipment [Member] | Maximum [Member]
Estimated useful life [Abstract]
Estimated useful life of intangible assets			7 years